I'm just taking a guess here, but I'd say most likely 640x480 (or whatever the equivalent is on a TV), because the xbox just doesn't have the power to push anything higher than that on a game like this

well that's what I think. I could, of course, be wrong

whatever it is, I'm sure it will look beautiful (though not as much as a really expensive PC http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif)